Has anyone had to replace the manifolds and riser pipe on a 496 HO and replaced with aftermarket Stainless Marine, Eddie Marine or some other aftermarket exhaust? If so, please share your experience. Were there any fit issues or reprogramming needed? I have to buy a new manifold and riser pipes so just trying to decide whether or not to change the factory setup or just go back with the stock exhaust system.

I have CMIs. Work great. Runs a little cooler. You gain midrange and quicker to top RPM. don't look for speed gains. Stock 496 exhaust isn't bad.

We have CMI Sport tubes on our 496HO twins. I concur with the above post. We did dyne testing before and after to prove horsepower gains. They really look good with the black motors. In addition, they sound much better than the stock exhaust. The sound is very simiar to 525's with Mercury headers.